Existing wash indicators on the market were and are designed primarily to monitor protein residuals or the effectiveness of alkaline cleaners. However, few if any of the currently and previously available wash indicators were able to monitor the effectiveness of pH neutral enzymatic cleaners and the presence of substrates that they were intended to remove. The prior indicators and systems were directed generally to protein, hemoglobin or fibrinogen. The prior wash indicators are simply not truly indicative of “clean” with respect to residues of other materials besides protein, hemoglobin or fibrinogen. However, multi-enzymatic cleaners are designed to remove or breakdown several organic soils in addition to protein, hemoglobin or fibrinogen.
The cleaning procedures in health care facilities have come under increasing scrutiny and the media has reported on various events where SSI (Surgical Site Infections) or HAIs (Hospital Acquired or Associated Infections) were acquired during routine procedures and some patients even died when various organic contaminants and bioburden were transmitted on contaminated surgical devices, even those visibly clean. For those devices that were seemingly clean (by visible inspection) it is clear that either small contamination levels not apparent to the naked eye AND/OR contaminants that are not visible because they have no visible light alteration properties so that they are “invisible” or “nonvisible” even if present in significant amounts are problematic and need to be addressed. These are not new problems, and have been around since the beginning of surgical techniques (if not earlier), but the concerns have been brought to the forefront of public awareness by the media.
The health care industry has used test soils that simulate organic soils to test the efficiency of cleaning systems. However, some are synthetic, a chemical or polymer that is washed away during reprocessing and supposedly designed to simulate true organic materials, but are not truly representative of the materials they are supposed to simulate. Some utilize hemoglobin and fibrin (a fibrous, non-globular protein involved in the clotting of blood, which is formed by the action of the protease thrombin on fibrinogen which causes the latter to polymerize. The polymerized fibrin together with platelets forms a hemostatic plug or clot over a wound site) on a substrate or coupon. However, the determination of results using these wash indicators rely on visual inspection only of an instrument or substrate to which the test soil is applied. This visual inspection provides a very limited way to determine if devices are safe for patient care.
Still, blood or fibrinogen may not be the most challenging of bodily materials to remove. Fat and brain tissue are particularly resistant to removal. When dried, these substances affix to stainless steel surfaces. Of particular concern is when inter-ocular tissue or neurological materials adhere to surgical devices. The user may not see any residual material with the naked eye, but believes that the device is safe to use on another patient. Blood with its distinctive color may be removed, but the “invisible” or “nonvisible” soil and bioburden can remain as residuals which are not recognized as being present.
The emergence of Creutzfeld Jackob Disease (CJD) transmissions from patient to patient via surgical procedures such as central nervous system, brain, eye, spleen, tonsils, appendix, as well as blood transfusions have pointed out the importance of routine monitoring of cleaning parameters beyond the visual check presently the norm in health care facilities. Moreover the presence of protein has been shown to increase corrosion of stainless steel instruments. In addition, the residual protein or lipids may promote adhesion of bacteria to device surfaces. The presence of protein and organic soil is also known to interfere with the sterilization process or further disinfection. Furthermore, staff may take short cuts, without recognizing the danger involved, when the requirement for inspection and release of devices is visual.
Each of the patents and patent applications mentioned in the next three paragraphs, are incorporated herein by reference in their entirety. To the extent that a statement in such reference is contrary to statements made herein (either made herein explicitly or implicitly) statements made herein shall prevail and the contrary or conflicting statement in the reference shall not be used to limit the scope of the invention. However, to the extent that any statement present in these references can provide support for a limitation to avoid prior art, either affirmatively or negatively, and applicant wishes to utilize such limitation in the claims, such shall be deemed incorporated, but only if and when Applicant requires such for introducing such a limitation into one or more claims.
US 20110291830 discloses a combination of a cleaning indicator, an associated test specimen, and a method for testing cleaning processes. This has a plurality of indicator elements on a common carrier to determine a differentiated determination of cleaning action.
WO97/27482 relates to sticking hemoglobin, a major component of blood, and albumin on a stainless steel plate with the use of fibrin. This, however, is not fully representative of bodily fluids or tissue. Blood is easily removed using an alkaline detergent, but alkaline detergents are corrosive to many devices used in surgical procedures. Further, tissue and fat are harder to remove than blood. Thus, the evaluation given by this disclosure is not completely suitable.
U.S. Pat. No. 5,726,062 discloses a method of detecting protein and a kit detecting protein using the same. A kit is disclosed, which includes a sampling means and a color forming reagent in combination. The step process disclosed is a multi-step process.
As discussed briefly above, there are additional challenges to medical device reprocessing due to the increasing complexity of surgical devices as well as emerging multiple drug resistant microorganisms and infectious agents that are difficult to remove from surfaces of devices and from lumens of minimally invasive devices present on surgical devices. These challenges, while previously present, have not been adequately addressed in the past other than in some instances to move to disposable equipment. As equipment becomes more complex and costly, the acceptability of “disposable devices” is simply not economically reasonable.